GraphQL on LinkedHashMap Data with schema and query

I have a requirement to transform the source JSON to a target JSON structure; for this, I am experimenting with GraphQL.

Below is my Java Code

String schema = "type Query{AuthToken: String}";

        SchemaParser schemaParser = new SchemaParser();
        TypeDefinitionRegistry typeDefinitionRegistry = schemaParser.parse(schema);

        DataFetcher<LinkedHashMap<Object, Object>> dataFetcher = environment -> {
            String json = "{\"AuthToken\":\"eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJjdXJyZW50QmF0Y2hOdW1iZXIiOiIxODk3MTczIiwidGVybWluYWxJZCI6InhucFByb2R1Y3QtT25saW5lIiwidXNlck5hbWUiOiJ4bnBVc2VyMSIsInBhc3N3b3JkIjoiQ24zdDNXaDlUZjlHYXBkT2RCamdNQTgrM1NZPSIsImVuYyI6InRydWUiLCJhdXRoVHlwZSI6IkJBU0lDIiwidG9rZW5UeXBlIjoieG5wX2F1dGhfdG9rZW4iLCJuYmYiOjE2NjI2NTIzMDMsImV4cCI6MTY2MjY1MjkwMywiaWF0IjoxNjYyNjUyMzAzLCJpc3MiOiJodHRwczovL3F3aWtjaWx2ZXIuY29tLyJ9.tiYe88waCpiWKAmYCkFyxxBCmuyFgLas_XsobFWxDrqfI9jzbrqQ1ZNiPdsovULd6xk1_0553aVOPJap15GE6Q\",\"ResponseMessage\":\"Transactionsuccessful.\"}";
            TypeReference<LinkedHashMap<Object, Object>> typeReference = new TypeReference<>() {
            };
            return mapper.readValue(json, typeReference);
        };

        RuntimeWiring runtimeWiring = newRuntimeWiring()
                .type("Query", builder -> builder.defaultDataFetcher(dataFetcher))
                .build();

        SchemaGenerator schemaGenerator = new SchemaGenerator();
        GraphQLSchema graphQLSchema = schemaGenerator.makeExecutableSchema(typeDefinitionRegistry, runtimeWiring);

        GraphQL build = GraphQL.newGraphQL(graphQLSchema).build();
        ExecutionResult executionResult = build.execute("{token: AuthToken}");

        log.info("GraphQL response {}", executionResult.getData().toString());

However, when this code is executed, GraphQL returns the complete JSON and not just the property AuthToken.

Also, the expected response is of structure

{token: 'the token from the input json' }

however, below response is received

{token={AuthToken=eyJhbGciOiJIUzUxMiIsInR5cCI6IkpXVCJ9.eyJjdXJyZW50QmF0Y2hOdW1iZXIiOiIxODk3MTczIiwidGVybWluYWxJZCI6InhucFByb2R1Y3QtT25saW5lIiwidXNlck5hbWUiOiJ4bnBVc2VyMSIsInBhc3N3b3JkIjoiQ24zdDNXaDlUZjlHYXBkT2RCamdNQTgrM1NZPSIsImVuYyI6InRydWUiLCJhdXRoVHlwZSI6IkJBU0lDIiwidG9rZW5UeXBlIjoieG5wX2F1dGhfdG9rZW4iLCJuYmYiOjE2NjI2NTIzMDMsImV4cCI6MTY2MjY1MjkwMywiaWF0IjoxNjYyNjUyMzAzLCJpc3MiOiJodHRwczovL3F3aWtjaWx2ZXIuY29tLyJ9.tiYe88waCpiWKAmYCkFyxxBCmuyFgLas_XsobFWxDrqfI9jzbrqQ1ZNiPdsovULd6xk1_0553aVOPJap15GE6Q, ResponseMessage=Transactionsuccessful.}}